Performance analysis of variable-power adaptive modulation with outdated feedback for space-time coded MIMO systems
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review
Author(s)
Related Research Unit(s)
Detail(s)
Original language | English |
---|---|
Article number | 6200888 |
Pages (from-to) | 2613-2624 |
Journal / Publication | IEEE Transactions on Vehicular Technology |
Volume | 61 |
Issue number | 6 |
Publication status | Published - Jul 2012 |
Link(s)
Abstract
The performance analysis of a space-time coded multiple-input-multiple- output (MIMO) system that employs different variable-power adaptive-modulation (VP-AM) strategies with outdated channel-state information (CSI) over Rayleigh fading channels is presented. The optimal design of VP-AM with power control (PC) in time (VP-AM-TIME) is first developed. The optimum switching thresholds of VP-AM-TIME for attaining maximum spectrum efficiency (SE) subject to a target bit error rate (BER) and an average power constraint are derived. A closed-form expression of the optimal temporal PC in terms of the Lambert function is obtained. A suboptimal VP-AM-TIME is also developed to further simplify the algorithm. The existence and uniqueness of the Lagrange multiplier that was used in the constrained optimization for the optimal and suboptimal VP-AM-TIME are investigated. By using the switching thresholds, we obtain closed-form expressions of SE and average BER. Then, a VP-AM scheme with joint spatial-temporal power control (VP-AM-JOINT) is developed. The joint spatial-temporal PC problem can be solved by transforming it into an inner-outer optimization problem. Theoretical analysis and simulation results show that the proposed optimal VP-AM-TIME can obtain the same performance as the existing optimal VP-AM-TIME but with much lower computational complexity, and the new suboptimal VP-AM-TIME outperforms the existing suboptimal scheme and obtains a performance closer to the optimal scheme. The results also show that the new VP-AM-JOINT scheme is always superior to the optimal VP-AM-TIME and provides considerable gains in SE over a wide range of feedback delays, although the two schemes have almost the same performance when the feedback delay becomes large. © 2012 IEEE.
Research Area(s)
- Adaptive modulation (AM), multiple-input-multiple-output (MIMO) system, outdated feedback, power allocation, space-time block code (STBC), variable power
Citation Format(s)
Performance analysis of variable-power adaptive modulation with outdated feedback for space-time coded MIMO systems. / Yu, Xiang-Bin; Leung, Shu-Hung; Kuang, Quan et al.
In: IEEE Transactions on Vehicular Technology, Vol. 61, No. 6, 6200888, 07.2012, p. 2613-2624.
In: IEEE Transactions on Vehicular Technology, Vol. 61, No. 6, 6200888, 07.2012, p. 2613-2624.
Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review